Products which combine multiple pharmaceutically active ingredients are available commercially throughout the world. Consumers purchase these medicaments because they relieve several symptoms at the same time. For example, ibuprofen and pseudoephedrine are sold in combination in solid forms, such as tablets, capsules, and powders for re-constitution. Ibuprofen is an effective analgesic/antipyretic agent, whereas pseudoephedrine is an effective decongestant. The combination of these two active ingredients is particularly effective for relieving sinus headaches, and symptoms of cold and flu. Ibuprofen and pseudoephedrine combinations are disclosed in U.S. Pat. No. 4,552,899.
While these products are known to be effective, consumers who use them are seeking faster symptom relief. Consequently, there continues to be a long felt need to develop products which bring rapid relief to the consumer.
Attempts have been made to improve the rate of onset of activity of various drugs by increasing their rates of absorption into the bloodstream following oral administration. For example, PCT application WO98/38983 discloses a method of improving the absorption rate of the analgesic, paracetamol, by combining it with sodium bicarbonate in a tablet or capsule formulation in a specific weight ratio. Irwin et. al. [J. Pharm. Sci, 58(3), March 1969] demonstrated enhanced absorption of the quaternary ammonium compound, isopropamide, when it was administered in combination with a large molar excess of trichloroacetate in solution. Meyer and Manning [Pharm. Res. 15(2), 1998] discuss the use of hydrophobic ion pairing to enhance the bioavailability of poorly lipid-soluble protein and peptide drugs.
It has now been found, unexpectedly, that the absorption rate of a pharmaceutically active amine (such as pseudoephedrine) is improved when the amine is formulated together with an acidic non-steroidal anti-inflammatory drug (such as ibuprofen) in a liquid medium.